The present invention relates generally, as indicated, to pollution control, namely filtering of particulate matter and more specifically to apparatus and method for filtering dust or other particulates from a carrier medium, such as air.
Pollution control equipment often is used in various environments, such as in an industrial plant, to remove dust or other particulate matter. As used herein dust means lightweight or heavy particulate matter; examples may be lightweight dust ordinarily carried by natural air currents, sawdust, metal chips, ceramic dust, coal dust, rock dust, and other heavier particulate matter that may be drawn and carried by a carrier fluid, such as an air stream provided by a suction device. Air is described herein as the preferred carrier fluid, but it will be appreciated that the principles of the invention may be employed using other carrier fluids.
Typically dust laden air, sawdust, etc. are drawn from a production environment, for example, via a pneumatic suction apparatus. The output from such suction apparatus is a flowing stream of dirty (dust laden) air. To separate the dust from such dirty air a filtering or separation process is required. For example, the dirty air may be fed to a cyclone separator of conventional design in which the particulate matter is removed from the air and is collected for disposal. The clean air leaving the cyclone separator may be discharged into the surrounding environment or may be filtered by a secondary filter, such as a conventional bag filter.
Air entering such a conventional bag filter is filtered by filter bags therein and is discharged through the walls of the filter bags. The dust, on the other hand, remains in the filter bags. Relatively frequent cleaning of the filter bags is required. Such cleaning usually entails cleaning of the individual filter bags or replacement thereof. Moreover, such cleaning maintenance may require shut-down of the main pollution control equipment, which is undesirable during operational production hours in a plant, possibly causing a temporary plant shut-down during such maintenance, and would be expensive because of overtime labor if the maintenance is performed after ordinary working hours.